This invention relates to a marine propulsion unit and more particularly to an improved outboard motor construction that assists in bringing the associated watercraft into a planing condition.
It is well known that a wide variety of outboard motors have been proposed which are mounted on the transom of an associated watercraft and which operate to propel the watercraft. The most commonly utilized type of watercraft hull propelled by outboard motors is a so-called planing type of hull. With this type of hull, at low speeds the hull becomes relatively deeply submerged but as the boat approaches its planing speed, it will move upwardly so as to substantially reduce the amount of water which the hull displaces. However, when accelerating the weight of the outboard motor on the transom tends to cause the transom to move downwardly and the bow move upwardly so as to increase the resistance to reaching the planing condition. The only way the watercraft can then be moved into the planing condition is to either increase the amount of power or to employ some kind of a plate or dynamic lift device at the stern of the boat or at the rear of the marine propulsion unit so as to arrive in the planing condition.
It is, therefore, a principal object of this invention to provide an improved marine propulsion unit that will assist in achieving planing of the associated watercraft but which will not afford significant restriction when traveling at high speeds.
The prior art type of dynamic lift devices have provided a drag that reduces the high speed operation. It is, therefore, a still further object of this invention to provide an improved outboard motor construction which will provide a buoyant lift for the transom of the watercraft when traveling at low speeds but which will be out of the water and afford no drag when reaching the planing condition.